1. Field of the Invention
This invention relates to a method and apparatus for recording compressed audio data transmitted over a transmission medium. More particularly, it relates to a method and apparatus for recording audio data on a recording medium, in which the recorded audio data can be randomly accessed using TOC information.
2. Related Art
There has so far been known a magneto-optical disc, known as a mini-disc (trade mark) which is a disc-shaped recording medium approximately 64 mm in diameter held in a cartridge for recording/reproducing audio data. This magneto-optical disc can record stereo audio data continuing for approximately 74 minutes using an Adaptive Transform Acoustic Coding (ATRAC) system for audio as an audio compression system. Since the magneto-optical disc is small-sized and excellent in portability, it can be taken outdoors easily. Moreover, in contradistinction from the conventional so-called compact disc (trade mark), the mini-disc; can record data so, it can be used for duplicating audio data.
Similarly to the conventional digital audio disc, the magneto-optical disc can randomly access recorded audio data, because the magneto-optical disc has not only an area for recording audio data but also a Table-Of-Contents area (TOC area) to control the recorded audio data. Therefore, in overwriting audio data on the magneto-optical disc having recorded audio data, musical numbers can be erased or edited by re-writing the TOC information without the necessity of re-writing the music data itself.
In transmitting compressed audio data over transmission channels, such as satellite broadcasting or public networks, it may be envisaged for a reception apparatus side to record compressed audio data transmitted from a transmitting apparatus side without expanding the data.
The recording medium loaded for this audio dubbing system is not necessarily an initialized disc (xe2x80x98virginxe2x80x99 disc) but may be a partially recorded disc. In the case of an audio dubbing system in which, before starting dubbing, the residual recording capacity of the recording medium loaded on the side of the reception apparatus is previously transmitted to a transmission apparatus which then receives the compressed audio data, an inconvenience arises that the confirmation operation needs to be carried out bidirectionally.
Since the confirmation operation is required before starting dubbing, there elapses time before starting the data distribution operation.
It may be contemplated to transmit the control information after distributing a series of compressed audio data. However, if the compressed audio data of a sum total of three musical numbers, each continuing for five minutes, with the total time being 15 minutes, and the residual recording capacity of the recording medium is 10 minutes, it is only after transmission of the compressed audio data and the control information completely comes to a close that the reception apparatus side can comprehend that the 5-minute portion of the transmitted data cannot be recorded on the recording medium.
Stated differently, it is after lapse of 15 minutes after start of dubbing that it is comprehended that the third musical number as the last musical number cannot be recorded.
In addition, since the control information is transmitted after completion of transmission of audio data, the title name or the relevant picture information of compressed audio data being recorded on the recording medium cannot be displayed during recording.
It is an object of the present invention to provide an distribution system, an distribution method and a reception method and apparatus whereby compressed audio data and the relevant information of the compressed audio data, such as data size data, picture information or text information, are packeted and transmitted or received by time divisional multiplexing from one packet to another.
In one aspect, the present invention provides a distribution system including blocking means for blocking a compressed audio program distributed from an information center and the relevant information concerning the distributed audio program, transmitting means for transmitting compressed audio program and the relevant information blocked by said blocking means by time division multiplexing, reception means for receiving the compressed audio program and the relevant information transmitted from said transmitting means by time division multiplexing, separation means for separating the audio program and the relevant information received by said reception means from each other, recording means for recording the compressed audio program separated by said separation means on a recording medium and advising means for advising a user of the relevant information separated by said separation means.
In another aspect, the present invention provides an distribution method including blocking a compressed audio program distributed from an information center and the relevant information concerning distributed audio program, transmitting the compressed audio program and the relevant information blocked by said blocking means by time division multiplexing, receiving the compressed audio program and the relevant information transmitted from said transmitting means by time division multiplexing, separating the audio program and the relevant information received by said reception means from each other, recording the compressed audio program separated by said separation means on a recording medium and advising a user of the relevant information separated by said separation means.
In still another aspect, the present invention provides a transfer/reception system for transferring at least one compressed audio program and receiving the transferred compressed audio program, the transferring system including generating means for generating capacity size information corresponding to the compressed audio program, transferring means for transferring the compressed audio program and the capacity size information corresponding to the compressed audio program, and the receiving system including receiving means for receiving the compressed audio program and capacity size information corresponding to the compressed audio program, generating means for generating the management information in accordance with the capacity size information corresponding to the compressed audio program, recording means for recording the compressed audio program and the management information in the recordable area and in the management area of the recording medium, respectively, whereby the transferred compressed audio program is divided into plural compressed audio programs in accordance with the capacity size information.
In yet another aspect, the present invention provides a transferring/receiving method for transferring at least one compressed audio program and receiving the transferred compressed audio program, including generating capacity size information corresponding to the compressed audio program, transferring the compressed audio program and the capacity size information corresponding to the compressed audio program, receiving the transferred compressed audio program and the capacity size information corresponding to the compressed audio program, generating the management information in accordance with the capacity size information corresponding to the compressed audio program and recording the compressed audio program and the management information in the recordable area and in the management area of the recording medium, respectively, whereby the transferred audio program is divided into plural compressed audio programs in accordance with the capacity size information.
According to the present invention, the compressed audio program distributed from the information center and the relevant information concerning the distributed audio program are blocked and transmitted by time division multiplexing, so that, if the reception side apparatus receiving the compressed audio program decodes the relevant information, it is possible to display the title name of the received audio program, pictures or photos of a producer or introductory columns of the contents producer.
In addition, recording can be started promptly without advising the transmitting side prior to start of recording of the recordable residual amount of the recording medium loaded on the reception side.
Moreover, since the reception side can comprehend the capacity of the compressed audio program being recorded, on decoding the relevant information concerning the distributed audio program, as a result of transmission of the sequentially compressed audio program and the relevant information, it is possible to issue an alarm concerning the shortage of the recordable residual amount promptly by comparing the residual amount of the recording medium and the recording capacity of the received compressed audio program prior to recording.